Saving Pennies or Dollars is a new semi-regular series on The Simple Dollar, inspired by a great discussion on The Simple Dollar’s Facebook page concerning frugal tactics that might not really save that much money. I’m going to take some of the scenarios described by the readers there and try to break down the numbers to see if the savings is really worth the time invested.

Darrin said, Driving around town looking for the cheapest gas prices for the day. Yes there are apps and web sites that tell you all that, but I don’t think about filling the car when I’m in front of my computer. I found a gas station that is usually a couple cents above the lowest prices, but it’s on my route to work so I stick to it now and have more time.

Let’s say, for instance, that you are driving a car that needs ten gallons in it and you only save $0.05 per gallon by driving around. That’s $0.50 in savings. If you’re driving a truck that needs eighteen gallons and you find a place that saves you $0.10 per gallon, that’s $1.80 in savings.

No matter what you do to save gas, you’re talking about a small amount per fill-up. If you drive around looking for cheaper gas, not only are you spending time doing this, but you’re burning gas in the process.

In my opinion, driving more than a few blocks for cheaper gas isn’t worth it. Even if you’re saving $1.80 in the optimum situation above, you’re still burning a bit of gas to get there and a bit of time to drive that extra distance. If you go further than that, your money saved continues to drop and your time spent continues to grow.

There’s also the factor that sites and tools that give you updated gas prices aren’t perfect. More than a few times, I’ve discovered the hard way that the prices listed in these tools isn’t accurate. Someone has uploaded bogus data as a prank or as a simple user error or the tool is outdated. When these sites work, they work; when they don’t, they don’t.

Instead, I use a completely different approach for gas. I invest some time up front figuring out which local station(s) consistently have the cheapest price on gas, then I use that station (or stations) as my primary place for filling up. Here’s what I do.

I monitor the gas price comparison sites for a week or two to see which stations in my area have the cheapest gas. This is really the backbone of my plan. If you’re in an area where prices are updated frequently, you can easily get a sense of which stations are consistently the lowest by watching such comparison data.

I also look for stations that have special deals in addition to the normal gas price. For example, the local Sam’s Club offers discounted gas to members and the local Hy-Vee Gas offers a discount if you bring in a recent receipt from a nearby Hy-Vee grocery store. Other gas stations offer tremendous discounts if you use their credit card.

Once I have this information in hand, I figure out which gas station is consistently the lowest (or tied for the lowest) in terms of gas prices. Usually, this is pretty straightforward once you know some of the offers available at the gas stations and what their regular prices are.

The winning gas station simply becomes my regular gas station. I use it for all of my gas purchases for a while until I get a sense that perhaps I should recalculate

While this process doesn’t guarantee me the lowest gas price at each fillup, it does ensure that I have one of the lowest gas prices around at every fillup. Even better, I’m not driving around to find this bargain. It’s usually a station along my regular route for groceries or other goods.

To put it simply, driving around looking for the cheapest gas saves pennies (at best), while figuring out your cheapest gas station in advance then using it regularly saves dollars over the long haul.

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